docs: def get_prefix(self, name):
          """
          Retrieve a prefix, resolving the current one if needed
  
          Args:
              name(str): name of the prefix to retrieve, or current to get the
                  current one
  
          Returns:
              self.prefix_class: instance of the prefix with the given name
          """
          if name == 'current':
              name = self.current
  
          try:
              return self.prefixes[name]
          except KeyError:
              raise KeyError(
                  'Unable to find prefix "%s" in workdir %s' % (name, self.path)
              )